Abstract

Contributed Talk - Splinter MassiveStars

Monday, 09 September 2024, 16:35   (S23)

First VLTI/MATISSE observations of the core region of IRS13 in the vicinity of Sgr A*

E. Bordier, L. Woglo, F. Peissker, L. Labadie
I. Physikalisches Institut

The innermost parsec of the Galactic Centre hosts the supermassive black hole SgrA* along with a population of young massive stars. Located at 0.13 pc from SgrA*, the IRS 13 cluster harbors a handful of luminous WR/O objects as well as a putative IMBH. Among them, E1 and E2 are prominent and bright sources, classified respectively as an OB supergiant and a WN8 based on their near-infrared spectra. Some authors suggest that both stars significantly contribute to the X-ray emission of IRS13 in the form of colliding stellar winds and the interaction of which with the ISM shapes the tail-like feature of the cluster. Yet, the exact nature of these sources has not been revised since 2004. With the advent of high-angular resolution techniques such as long-baseline optical interferometry, it is now possible to further characterize the typical sizes and morphological properties of these objects. We present here the first attempt to observe and resolve E1 and E2 using the VLTI/MATISSE instrument. Our findings reveal that both sources are resolved in the continuum visibilities, showing a fully resolved component at mid-IR wavelength and an unresolved central star modelled with a blackbody of Teff>25,000K. Additionally, We suggest that both objects could be surrounded by an optically thin envelope of T~500K that extends over several hundred astronomical units, whose sublimation radius might be smaller than the outer edges of the envelope. These results, although preliminary, highlight the potential of optical interferometry to uncover the infrared structure of these massive objects and to better understand their influence on their immediate surroundings.